Turndown Ratio

Turndown Ratio describes the difference between the highest and lowest possible span of measurement output which can be set for a sensing device with a rangeable output signal such as 4 to 20mA output which is HART enabled.

Turn-down ratio refers to rangeable output devices and indicates how much the output setting can be changed.

e.g. A 10:1 turndown ratio on a 1 bar gauge pressure transmitter would allow the following:

●Highest range setting: 0 to 1 bar absolute = 4 to 20mA
●Lowest range setting: 0 to 100 mbar absolute = 4 to 20mA